Firefox

Firefox is Mozilla's popular Web browser, available for multiple platforms including Windows, OS X, and Linux on the desktop and all Android mobile devices. With broad compatibility, the latest in Web technologies, and powerful development tools, Firefox is a great choice for both Web developers and end users.

Firefox is an open source project; most of the code is contributed by our huge community of volunteers. Here you will learn about how to contribute to the Firefox project and you will also find links to information about the construction of Firefox add-ons, using the developer tools in Firefox, and other tasks.

Learn how to create add-ons for Firefox, how to develop and build Firefox itself, and how the internals of Firefox and its subprojects work.

Get detailed information about the internals of Firefox and its build system, so you can find your way around in the code.

Developer guide

Our developer guide provides details on how to get and compile the Firefox source code, how to find your way around, and how to contribute to the project.

Firefox channels

Firefox is available in four channels.

Firefox Nightly

Each night we build Firefox from the latest code in mozilla-central. These builds are for Firefox developers or those who want to try out the very latest cutting edge features while they're still under active development.

Firefox Developer Edition

This is a version of Firefox tailored for developers. Every six weeks, we take the features in Firefox Nightly that are stable enough and create a new version of Firefox Developer Edition. We also add some extra features for developers that are only available in this channel.

Firefox Beta

After spending six weeks in Firefox Developer Edition, we take the features that are stable enough, and create a new version of Firefox Beta. Firefox Beta builds are for Firefox enthusiasts to test what's destined to become the next released Firefox version.